Neuroscience is the scientific study of the nervous system. Traditionally, neuroscience has been seen as a branch of biology. However, it is currently an interdisciplinary science that collaborates with other fields such as chemistry, computer science, engineering, linguistics, mathematics,...

Neurotheology, also known as spiritual neuroscience, is the study of correlations of neural phenomena with subjective experiences of spirituality and hypotheses to explain these phenomena....

. Originally called the "Koren helmet" after its inventor Stanley Koren, it was conceived to study creativity and the effects of subtle stimulation of the mesiobasal temporal lobes. Reports by participants of a "sensed presence" brought public attention to the God Helmet through appearances in several TV documentaries showing it in use.

The apparatus, placed on the head of an experimental subject, generates weak fluctuating (i.e. "complex") magnetic fields. These fields are approximately as strong as those generated by a land line telephone handset or an ordinary hair dryer, but far weaker than that of an ordinary fridge magnet. It is used extensively by Michael Persinger

Michael Persinger

Michael A. Persinger is a cognitive neuroscience researcher and university professor with over 200 peer-reviewed publications. He has worked at Laurentian University, located in Sudbury, Ontario, since 1971.-Early life:...

Laurentian University , was incorporated on March 28, 1960, is a mid-sized bilingual university in Greater Sudbury, Ontario, Canada....

in Sudbury, Ontario, Canada. Persinger has published extensively about the effects on the human brain of the "complex" magnetic fields generated by the God helmet and other similar devices. Many subjects have reported "mystical experiences and altered states" while wearing the God Helmet. Although demonstrated to journalists and documentarists, these effects await the publication of independent replications

Reproducibility

Reproducibility is the ability of an experiment or study to be accurately reproduced, or replicated, by someone else working independently...

in formal peer-reviewed scientific journals. The only attempt at replication published in the scientific literature reported a failure to replicate Persinger's effects. Persinger claims the replication was flawed. The Swedish group disagrees.

Persinger reports that at least 80 percent of his participants experience a presence beside them in the room, which ranges from a simple 'sensed presence' to visions of God

God

God is the English name given to a singular being in theistic and deistic religions who is either the sole deity in monotheism, or a single deity in polytheism....

. About one percent experienced God, while many more had less evocative, but still significant experiences of "another consciousness or sentient being". The God Helmet has received attention from the media and theologians because of the challenge it appears to present to traditional beliefs in God. Although only a small number (on the order of 1%) of the experimental subjects saw God in the laboratory, their experiences can be interpreted as meaning that God is the subjective experience of an unusual kind of brain function. In contrast, most of the subjects had the experience of 'sensing' a 'presence'.

Theory

The God Helmet was not specifically designed to elicit visions of God. Like most experiments, the God Helmet procedure was designed to test specific hypotheses. The first of these is the "vectorial hemisphericity" hypothesis, which proposes that the human sense of self has two components, one on each side of the brain, that ordinarily work together but in which the left hemisphere is usually dominant. The two hemispheres make different contributions to a single sense of self, but under certain conditions can appear as two separate 'selves'. The God Helmet was designed to create conditions in which contributions in tandem to the sense of self from both cerebral hemispheres is disrupted.

The second experimental hypothesis was that when communication between the left and right senses of self is disturbed, the usually-subordinate 'self' in the right hemisphere intrudes into the awareness of the left-hemispheric dominant self, causing what Persinger refers to as "interhemispheric intrusions".

The third hypothesis was that the variety of "visitor experiences" can be explained by "interhemispheric intrusions" caused by a disruption in "vectorial hemisphericity". Persinger claims that many paranormal experiences, feelings of having lived past lives, felt presences of non-physical beings, ghosts, muses, and other "spiritual beings", are examples of interhemispheric intrusions.

The God Helmet experiments were also intended to validate the idea that religious and mystic experiences are artifacts of temporal lobe function.

Methods

Persinger uses a modified snowmobile helmet that incorporates solenoids placed over the temporal lobes. His formal name for the equipment is the "Koren Helmet" (after its inventor, Stanley Koren). He also uses a device nicknamed "The Octopus" which uses solenoids around the whole brain

Brain

The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...

, in a circle just above subject's ears. Both of these devices produce "weak but complex" (1 microTesla) magnetic fields.

A computer is used to control the solenoids, the outputs of which are amplitude-modulated and non-sinusoidal (which Persinger refers to as "complex"). Most of the signals employed are derived from physiological sources, for example patterns that appear in EEG traces taken from limbic structures. Only one of the coils on each side of the helmet is active at any one time, and the active coil changes constantly, "rotating" counterclockwise over each temporal lobe. Persinger's God Helmet sessions consist of two stimulations, applied one after the other. The first of these uses a signal "tailored from a chirp sequence", applied over right temporal lobe. In the second phase of the procedure, both temporal lobes are stimulated, with a pattern derived from the amygdala.

The sessions are conducted with the subject seated in a comfortable chair in an acoustic chamber. The acoustic chamber is also a Faraday cage

Faraday cage

A Faraday cage or Faraday shield is an enclosure formed by conducting material or by a mesh of such material. Such an enclosure blocks out external static and non-static electric fields...

, shielding out all EMF emissions and radiation except the Earth's magnetic field. This shielding allows Persinger to use the apparatus to investigate the effects of geomagnetism on the human brain.

Experiences

Persinger claims that this pattern of stimulation can temporarily alter some of the brain activity critical for maintenance of the normal sense of self. It is supposed that during right temporal lobe stimulation the right hemisphere becomes more active, including the more sensitive structures in the limbic system

Limbic system

The limbic system is a set of brain structures including the hippocampus, amygdala, anterior thalamic nuclei, septum, limbic cortex and fornix, which seemingly support a variety of functions including emotion, behavior, long term memory, and olfaction. The term "limbic" comes from the Latin...

. As this happens, the left side of the brain makes fewer contributions to the subject's state of consciousness. The resulting state of consciousness is less verbal, and in some cases, more apprehensive, even fearful. In one case this stimulation, applied alone, elicited the experience of a frightening ghost for a subject who had the experience previously.

When both lobes are stimulated, Persinger claims, the left side of the brain responds with a burst of activity, and it's at this point that a visitor experience is most likely to appear. In a few oft-mentioned cases from Persinger's lab, the visitor experience has been one of God, but much more often, it's a simple sense of a presence, or a vision of an angel, a deceased being known to the subject, or a group of beings of some kind. A feeling of meaningfulness can occur as the left limbic system is abruptly activated by the change in the stimulation, so that the subject might feel it "means something", infusing the experience with a sense of importance. This kind of meaningfulness is a component of what Persinger calls "The God Experience". The transient above-normal left hemispheric activity also enhances positive affect, a term that embraces bliss and ecstasy, one of the most common features of the "God Experience".

Use of the God Helmet in the treatment of depression

Persinger's group has also used the God Helmet to study clinical depression. One study found "a significant improvement of depression and reduction of phobias" following application of the God Helmet once a week for five weeks. Another study found that the stimulation was equally effective when applied over either the frontal or temporal lobes, and that complex epileptic signs decreased significantly, but only when the magnetic fields were applied over the temporal lobes (the normal location for the God Helmet's magnetic coils). In another study, "the burst-firing pattern previously demonstrated to be effective for clinical depression, improved mood and vigour compared to the sham-field or other treatments". The experimental report concluded that "rationally designed complex patterns of magnetic fields may simulate pharmacological treatments".

Replication attempts and subsequent debate

Nature, first published on 4 November 1869, is ranked the world's most cited interdisciplinary scientific journal by the Science Edition of the 2010 Journal Citation Reports...

reported that a group of Swedish researchers led by Pehr Granqvist, a psychologist

Psychologist

Psychologist is a professional or academic title used by individuals who are either:* Clinical professionals who work with patients in a variety of therapeutic contexts .* Scientists conducting psychological research or teaching psychology in a college...

Uppsala University is a research university in Uppsala, Sweden, and is the oldest university in Scandinavia, founded in 1477. It consistently ranks among the best universities in Northern Europe in international rankings and is generally considered one of the most prestigious institutions of...

Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....

, had attempted to replicate Persinger's experiments under double-blind

Double-blind

A blind or blinded experiment is a scientific experiment where some of the people involved are prevented from knowing certain information that might lead to conscious or subconscious bias on their part, invalidating the results....

conditions, and were not able to reproduce the effect. The study was published in Neuroscience Letters

Neuroscience Letters

Neuroscience Letters is a rapid-publication weekly scientific journal for short articles covering all aspects of neuroscience....

Religious experience is a subjective experience in which an individual reports contact with a transcendent reality, an encounter or union with the divine....

reported by the participants, but was predicted entirely by their suggestibility and personality traits.
Persinger, however, takes issue with the Swedish attempts to replicate his work. "They didn't replicate it, not even close," he says. He argues that the Swedish group did not expose the subjects to magnetic fields for long enough to produce an effect. Dr. Granqvist, however replied that Dr. Persinger agreed to a 15 minute time period for PET study beforehand. Persinger also stresses that many of his studies were indeed double blinded The Swedish group disagree.

The British Broadcasting Corporation is a British public service broadcaster. Its headquarters is at Broadcasting House in the City of Westminster, London. It is the largest broadcaster in the world, with about 23,000 staff...

science documentary series Horizon, did not have a 'sensed presence' experience, but instead felt at times 'slightly dizzy', 'quite strange' and had sensations in his limbs and changes in his breathing. He summarised his experience as follows: "It pretty much felt as though I was in total darkness, with a helmet on my head and pleasantly relaxed". Persinger explained Dawkin's limited results in terms of his low score on a psychological scale measuring temporal lobe sensitivity.

The term parapsychology was coined in or around 1889 by philosopher Max Dessoir, and originates from para meaning "alongside", and psychology. The term was adopted by J.B. Rhine in the 1930s as a replacement for the term psychical research...

Susan Jane Blackmore is an English freelance writer, lecturer, and broadcaster on psychology and the paranormal, perhaps best known for her book The Meme Machine.-Career:...

said: "When I went to Persinger's lab and underwent his procedures I had the most extraordinary experiences I've ever had… I'll be surprised if it turns out to be a placebo

Placebo

A placebo is a simulated or otherwise medically ineffectual treatment for a disease or other medical condition intended to deceive the recipient...

effect."

Jack Hitt, a journalist from Wired magazine, visited Persinger's lab in 1999 and expressed confusion over Persinger's post-stimulation debriefing ("One question: Did the red bulb on the wall grow larger or smaller? There was a red bulb on the wall? I hadn't noticed.") and reported: "Many other questions suggest that there were other experiences I should have had, but to be honest, I didn't. In fact, as transcendental experiences go, on a scale of 1 to 10, Persinger's helmet falls somewhere around, oh, 4. Even though I did have a fairly convincing out-of-body experience, I'm disappointed relative to the great expectations and anxieties I had going in."

Other criticisms

Temporal lobe epilepsy a.k.a. Psychomotor epilepsy, is a form of focal epilepsy, a chronic neurological condition characterized by recurrent seizures. Over 40 types of epilepsies are known. They fall into two main categories: partial-onset epilepsies and generalized-onset epilepsies...

and religious experience, as discussed by Persinger, has been questioned. The auditory and visual hallucinations as well as emotional states experienced by Temporal Lobe epilepsy (TLE) patients during the seizure state typically induce sensations of malcontent, rather than ecstatic or pleasant sensations that are integral to spiritual experience, as noted by neurologist John R Hughes: "Auditory and visual hallucinations are very uncommon in epilepsy. Epileptic phenomena are nearly always brief and primitive, like light flashes" Persinger counters that even though only a small percent of TLE seizures include religious experiences, the study of these individuals nevertheless provides important evidence concerning the neural basis for religious and mystic experiences.

Persinger's findings regarding the effects of environmental geomagnetic activity have, to date, not been independently replicated. One published attempt to create a feeling of a "sensed presence" using an EM- and ultrasound-based "haunted room" instead of a God Helmet, found that reports of unusual experiences were uncorrelated with the presence or absence of "complex" environmental eletromagnetic fields similar to Persinger's. Reports of unusual experiences were however, predicted by the personality characteristics and suggestibility of participants.

Comparison with TMS

Transcranial magnetic stimulation is a noninvasive method to cause depolarization or hyperpolarization in the neurons of the brain...

(TMS). However, like TMS, this apparatus has also been used in studies of depression following closed-head brain injuries. TMS uses magnetic fields on the order of one million times stronger than those used in Persinger's lab, but Persinger reports similar effect sizes with his apparatus. The magnetic fields employed in TMS and in Persinger's experiments are also very different. TMS uses single, paired, and repetitive pulses of high intensity to penetrate the cranium. In contrast, Persinger's apparatus uses weak complex magnetic signals, including one derived from limbic burst firing.